2012-2013 neercshool 17 november Taks B

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <vector>
#include <map>
#include <set>
#include <ctime>
#include <cassert>
#include <queue>

using namespace std;

#define f first
#define s second
#define mp make_pair
#define pb push_back
#define forit(it,con) for (typeof(con.begin()) it = con.begin(); it != con.end(); ++it)
#define f0(a) memset(a, 0, sizeof(a))
#define all(v) v.begin(), v.end()
#define pii pair<int,int>
#define vi vector<int>
#define ll long long

#ifdef WIN32
    #define I64 "%I64d"
#else
    #define I64 "%lld"
#endif
char s[100];
int n;
struct node {
    int v;
    int n, p;
    node() {}
    node(int vv, int pp = 0, int nn = 0) {
        v = vv; p = pp; n = nn;
    }
} T[1000000];
int head, tail, mid, sz, m = 0;

void print() {
    int cur = head;
    for (int i = 0; i < m; ++i) {
        printf("%d ", T[cur].v);
        cur = T[cur].n;
    }
    printf("| %d %d %d\n", T[head].v, T[mid].v, T[tail].v);
}
int main() {
    freopen("kenobi.in","r",stdin);
    freopen("kenobi.out","w",stdout);


    scanf("%d", &n);
    sz = 1;
    for (int i = 0; i < n; ++i) {
        scanf("\n%s", s);
        if (s[0] == 'a') {
            int x;
            scanf("%d", &x);
            T[sz++] = node(x);
            T[sz - 1].p = tail;
            T[tail].n = sz - 1;
            tail = sz - 1;

            if (m % 2 == 1)
                mid = T[mid].n;
            ++m;
            if (m == 1) {
                head = tail = mid = sz - 1;
            }
        } else if (s[0] == 't') {

            if (tail) {
                tail = T[tail].p;
                T[tail].n = 0;
                if (m % 2 == 0)
                    mid = T[mid].p;
                --m;
                if (m == 0) {
                    head = tail = mid = 0;
                }
            }
        } else if (s[0] == 'm') {
            if (m > 1) {
                T[tail].n = head;
                T[head].p = tail;
                int pp = T[mid].p;
                T[pp].n = T[mid].p = 0;
                int nmid = head;
                if (m % 2 == 1) nmid = tail;
                head = mid; tail = pp;
                mid = nmid;
            }
        }

    }
    printf("%d\n", m);
    for (int i = 0; i < m; ++i) {
        printf("%d ", T[head].v);
        head = T[head].n;
    }
    return 0;
}